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1.
J Environ Biol ; 2005 Apr; 26(2): 299-300
Artigo em Inglês | IMSEAR | ID: sea-113361

RESUMO

Different nutrient elements were analyzed in the lichen Cryptothecia punctulata collected from the arecanut trees which were exposed to several sprays of a fungicide Bordeaux mixture. The study revealed the accumulation of fungicidal elements such as Cu, Ca and S in higher concentration of 575.4, 10,000 and 21,000 microg g(-1), respectively.


Assuntos
Areca , Cobre/metabolismo , Monitoramento Ambiental , Poluentes Ambientais/análise , Fungicidas Industriais/metabolismo , Índia , Líquens/química , Metais/análise , Resíduos de Praguicidas/análise
2.
J Environ Biol ; 2004 Jul; 25(3): 279-85
Artigo em Inglês | IMSEAR | ID: sea-113141

RESUMO

Rice seed grains exposed to 240 ppm of seed dressing fungicide, MEMC showed increase in deposition of mercury with increase in period of observation (0h to 48h) in 765+/-5 mg of intact endosperm. The gradual increase in mercury deposition in intact endosperm caused simultaneous decrease in mercury content of the seed coat. Exposure periods of 5 to 20 min with 240 ppm of MEMC showed 5.5 to 8.72 microg of mercury deposition in 765+/-5 mg of intact endosperm. Increase in period of exposure (3 to 20 min) to 240 ppm of MEMC and also increase in chronic treatment to lower concentrations (1.5 ppm to 24 ppm) to seed grains have shown similar results in seedling growth parameters. Lower period of exposure or exposure to lower concentrations, both showed a significant inhibition of root growth, however the shoot growth showed stimulation. But higher exposure period or exposure to higher concentrations brought inhibition of both root and shoot growth. The exposure period showing 50% of root growth inhibition of 72h old seedling was calculated to be 10 min So also the chronic treatment showing the 50% of root growth inhibition was calculated to be 9 ppm. Ten min exposure of rice grain to 240 ppm of MEMC showed deposition of 7.11 microg of mercury in 765+/-5 mg of intact endosperm at 48h of observation (optimal phase of germinating process). Regression analysis indicated that by the time of 72h the intact endosperm and developing seedling might have acquired with a minimum amount of 10.23 microg of mercury from the seed coat. Finally it can be said that 10.23 microg of MEMC might be bringing 50% root growth inhibition in 72h old seedlings and 16.71 microg of mercury causing 50% inhibition of both root and shoot growth of 120h old seedlings.


Assuntos
Fungicidas Industriais/metabolismo , Mercúrio/toxicidade , Oryza , Raízes de Plantas/efeitos dos fármacos , Brotos de Planta/efeitos dos fármacos , Medição de Risco , Plântula/efeitos dos fármacos , Fatores de Tempo
3.
Rev. microbiol ; 30(3): 265-71, jul.-set. 1999. tab, graf
Artigo em Português, Inglês | LILACS | ID: lil-253783

RESUMO

ß-Galactosidase or ß-D-galactohydrolase (EC.3.2.1.23) is an important enzyme industrially used for the hydrolysis of lactose from milk and milk whey for several applications. Lately, the importance of this enzyme was enhanced by its galactosyltransferase activity, which is responsible for the synthesis of transgalctosylated oligosaccharides (TOS) that act as functional foods, with several beneficial effects on consumers. Penicillium simplicissimum, a strain isolated from soil, when grown in semi-solid medium showed good productivity of ß-galactosidase with galactosyltransferase activity. The optimum pH for hydrolysis was in 4.0-4.6 range and the optimum pH for galactosyltransferase activity was in the 6.0-7.0 range. The optimum temperature for hydrolysis and transferase activity was 55-60§C and 50§C, respectively, and the enzyme showed high thermostability for the hydrolytic activity. The enzyme showed a potential for several industrial applications such as removal of 67 (per cent) of the lactose from milk and 84 (per cent) of the lactose from milk whey when incubated at their original pH (4.5 and 6.34, respectively) under optimum temperature conditions. When incubated with a 40 (per cent) lactose solution in 150 mM McIlvaine buffer, pH 4.5, at 55§C the enzyme converted 86.5 (per cent) of the lactose to its component monosaccharides. When incubated with a 60 (per cent) lactose solution in the same buffer but at pH 6.5 and 50§C, the enzyme can synthetize up to 30.5 (per cent) TOS, with 39.5 (per cent) lactose and 30 (per cent) monosaccharides remaining in the preparation.


Assuntos
beta-Galactosidase/metabolismo , Fungicidas Industriais/metabolismo , beta-Galactosidase/química , Fungicidas Industriais/química , Galactosiltransferases/metabolismo
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